Re: x86: get rid of the insane TIF_ABI_PENDING bit

From: Roland McGrath
Date: Mon Feb 15 2010 - 14:42:10 EST


> I suspect the purpose of TS_COMPAT is actually so you can ptrace() the
> newly exec'd process (and see it as a 32-bit process!) before it returns
> to userspace. The comment, obviously, is wrong -- that again refers to
> TIF_IA32.

I don't follow you. TS_COMPAT does not affect ptrace.
It affects syscall-audit, but only at syscall entry time.
It affects asm/syscall.h accessors, but ptrace does not use those.
It affects whatever uses is_compat_task(), but I can't see anything
where that matters except inside some particular syscall or for
syscall restart after signals.

TS_COMPAT does not affect the syscall return machinery itself.
The return path just follows from the particular entry path.


Thanks,
Roland
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